Heat exchanger



Jul so, 1935. R N. TRANE 2,009,863

HEAT EXCHANGER Filed Nov. 22; 1954, s Sheets-Sheet 1 INVENTCR f ZO/M' ATTORNEY R. N. TRANE HEAT EXCHANGER July 30, 1935.

Filed Nov. 22, 1934 3 Sheets-Sheet 2 .5

w 1 -iiiilikwiiil ENVENTOR MW ATTORNEY Jul 30, 1935. R, N, TRAN; 2,009,863

HEAT EXCHANGER Filed Nov. 22, 1934 5 Sheets-Sheet 3 INVENTOfi MW BY v ATTORNEY Patented July 30, 1935 UNITED STATES PATENT OFFICE 5 Claims.

My invention relates to a heat exchanger, particularly a heat exchanger designed for a gas to as or air to air transfer.

One of the objects of my invention is a compact air to air exchanger which can be economically and efficiently built.

Another object of my invention is the economical manufacture of an air to air exchanger wherein the header is made substantially all of one piece and the heat tubes are connected with said header plate in such manner as to form a gas-tight joint.

The various features of novelty which characterize my invention are pointed out in claims annexed to and forming a part of this specification, and the other features of novelty are pointed out in the specifications and the accompanying drawings which further illustrate my invention.

Figure 1 shows a side elevation of the exchanger.

Figure 2 shows an end elevation of the exchanger.

Figure 3 shows a cross-sectional elevation of the exchanger on the line 3--3 of Figure 2.

Figure 4 shows a front elevation of the header plate I I on the initial stamping of the header plate.

Figure 5 shows a cross-sectional elevation taken on the line 5-5 of Figure 4.

Figure. 6 represents a side elevation of the tube III.

Figure 7 represents a cross-section of the tube l0 taken on the line 'I'| of Figure 6.

Figure 8 represents a fractional portion of the header II, shown as an end elevation thereof.

Figure 9 shows a fractional cross-section of the heater taken on the line 9--9 of Figure 8,- showing a connection of the tubes into the header plate.

Figure 10 represents a cross-section of the tube III with a different construction, as shown in the specifications.

Figure 11 represents the side elevation of the tube I0 shown in Figure 10.

Figure 12 represents a side elevation of the tube In showing the corrugation.

Figure 13 represents a cross-section of the tube I0 on the line I3--I3 of Figure 12.

Referring to Figures 1 to 9 inclusive, I0 represents the heat tubes, II a header plate, I2 a header plate, which is identical with the header plate II with the inner sides of said plates facing each other, I3 a channel formed bead which is continuous and circumferential of the tube In, I4 represents gas or air passages, I5 an integral channel section formed out of the header plate I I and comprising integral flanges 28 formed at right angles to the header plate II, I6 represents the integral flanges of the header plate II formed at right angles to the header plate II to form the header chamber I'I. Asame chamber I1 is formed at the other end of the exchanger.

Dotted lines l8 in Figure 4 show the lines on which the header plate II is bent to form the header chamber. The apertures I9 are cut into the plate II, as shown in Figure 5 before stamping out the channel sections I5.

Referring to Figure 4, the corner 20 of the 10 header plate II is cut out on the dotted lines 2| and 22 so that when the headerplate is bent on the lines I8, the edges 2| and 22 meet to form a corner of the header chamber H, which corners may be welded or brazed in that position. The tube I II is preferably formed of a flat metal sheet having the channel shaped bead initially stamped therein, the sheet being then folded to form a flattened tube with a contour as shown in Figure 7, in which 23 represents the wall of the tube and 24 a lock seam joint, forming an ordinary gastight joint which may further be made gas-tight by welding or brazing. The flattened tube is then composed of two flattened sides in parallel, or substantially parallel, relationship, joined together by arcuate side portions of small area as compared to the flat surface.

The beads in the tube may be formed by either corrugating the flat sheet before forming into a tube or by corrugating the metal after the tube has been formed. The tubes Ill formed as shown in Figure 6 are then forced through the openings 26 of the header plate II, as shown in Figure 3, and the end portions 25 of the tube II] are then turned over on the flanges 28 of the channel section I5 to form the joint 29. The lock seam joint thus formed is then pressed together to form an ordinary gas-tight jpint which, if desired, may be made absolutely tight by welding or brazing. The bead I3 abuts the corner 21 of the header. II in such a way that when the end portion 25 is turned over on the flanges 28, the tube I0 is securely locked into place with reference to the plate I I. This is very important because any expansion of the tube would have a constant 45 tendency to work on the joint 29, thus impairing its usefulness as a gas-tight joint.

It is obvious that under this construction any movement of the tube toward the header is resisted by the bead I3, which fits snugly against 50 the corner 21. The bead I3 has a further purpose of spacing the amount of tube which is to be allowed to extend through the plate II, which is pre-determined and enables the automatic manufacture of the exchanger with tools designed to peen over and press together a pre-determined portion 25 of the tube. The bead II has a further purpose of spacing the amount of tube between the beads which is available for heat transfer surface. I

Insome uses of the exchanger the expansion of the side walls of the tube l0 may cause the metal to bend across center and to avoid that, another construction of the tube I0 is shown in Figures 10 to 13 inclusive. In Figures 10 and 11 the tube I0 is shown as being bowed, in which the diameter of the tube I0 is greater at the center, for example, on the dotted line 33 than it is toward thevends of the tubes as on the dotted lines 3| and 32.

In Figure 11 the tube is shown bowed out so that the diameter of the tube at the center, to-wit, on

the dotted line 33, is greater than the diameter toward the end of the tube, as on the line 34. In both ofthese figures, the numerals 3 5 and 36 represent opposite side walls of the tube.

In Figure 12, which shows a plan view of the side wall 35, 1! represents a diagonal corrugation designed to allow an easy expansion and contraction ofthe side wall 35 without havin the side wall make any noise in going across center. v

In the operation of the exchanger, gas or air is forced into the gas chamber I1 and through the tubes iii in one direction while gas or air is forced past the tubes ll through the spaces It in a flow at right angles to the flow of the first gas. The bead shape of the tube shown is conducive to a long travel of the gases in a heat exchanger with gases traveling crass-wise and results in very efilcient heat exchange. The rounded or arcaic portions of the flattened tube are designed to ofi'er small resistance to the travel of the air or gas against the ends and through the spaces IQ.

In an exchanger of this sort it is generally important that it be gas-tight, at least so far as the travel of one gas is concerned, and for that reason the gas chamber or header chamber I! is formed with side walls integral with the header plate.

Although one specific embodiment of the invention has been particularly shown and described, it will be understood that the invention is capable of modification and that changes in the construction and in the arrangement of the various cooperating parts may be made without departing from the spirit or scope of the invention, as expressed in the following claims. i

What I claim is:

1. In a gas to gas heat exchanger, the combination of flattened tubes each having an interlocking seam extending substantially throughout its length but terminatingshort of its ends, a circumferential bead thereon spaced from the ends of each of said tubes and adjacent the ends of such interlocking seam, a header plate with apaooases erturestherein and having flanges integral with said header and at right angles thereto, said tubes being inserted in said apertures so that said beads abut the inner side of said header plates,

with the end portions of said tubes being rebent and pressed together over the said flanges to form a seam.

2. In a gas to gas heat exchanger, the combination of flattened tubes each having an interlocking seam extending substantially throughout its length but terminating short of its ends, a circumferential bead thereon spaced from the ends of each of said tubes, and adjacent the ends of such interlocking seam, a header plate with apertures therein and having flanges integral with said header at right angles thereto, said tubes being inserted in said apertures so that said beads abut the inner sides of said header plates, with the end portions of said tubes being rebent and pressed together over the said flanges to form a seam, and flanges integral with and at right angles to saidheader plates forming the side walls of header chambers.

3. In a gas to gas heat exchanger, the combination of flattened tubes each having an interlocking seam extending substantially throughout its length .but terminating short of its ends, a circumferential bead thereon spaced from the ends of each of said tubes and adjacent the ends of such interlocking seam, a header plate with apertures therein and having flanges integral.

with said header and at right angles thereto, said tubes being inserted'in said apertures so that said beads abut the inner sides of said header plates, with the end portions of said tubes being rebent and pressed together over the said flanges to form a seam, and flanges integral with and at right angles to said header plates, said flanges being welded together to form the header chamber. s

4. In a gas to gas exchanger, the combination of flattened tubes, each formed with a longitudinal seam extending substantially the length thereof, spaced circumferential beads adjacent the ends of the tubes, a header plate with apertures therein, said tubes-being inserted in apertures so that said beads abut the edges of said apertures, with the end portions of said tubes being'bent over against the outer side of said headerplate to form a Joint.

5. In a heat exchanger, the combination of flattened tubes formed with circumferential beads adjacent the ends thereof for abutment against opposing headers with which said tubes are connected, the said tubes each being formed with a diagonally disposed convex ridge in the region of its mid-length thereby to obviate noise. in the expansion and contraction of the tubes and to direct the fluid in its e therearound.

REUBEN N. TRANE. 

